Python Exception Handling Quiz

Exception Handling in Python

• Python programs can encounter errors during execution.
• These errors, called exceptions, disrupt normal execution if not handled.
• Exceptions are Python objects with specific types.
• Python provides mechanisms to handle and manage exceptions.
• Syntax errors, which occur when code violates the language's rules, cause immediate termination and error messages.
• Runtime errors such as division by zero cause the program to stop abruptly.
• Exception handling prevents unexpected program termination.
• Exceptions may occur during execution but should be anticipated.
• The try block encloses code that might cause an exception.
• The except block handles specific exceptions within the try block.
• Exception handling improves program robustness. The exceptions are handled and the user is given a suitable message.

1.1 Introduction

• Python programs may not execute as intended sometimes due to errors in syntax, logic, or runtime.
• These errors can cause the program to crash or produce unexpected output.
• Syntax errors are errors in the formatting of the Python code.
• Runtime errors are errors that occur when the program is running, such as trying to divide by zero or accessing a non-existent file.
• Logical errors are errors within the program logic which cause unexpected output.
• Exception handling is a significant factor for Python programming that prevents crashes and enhances program robustness.

1.2 Syntax Errors

• Syntax errors occur when the code doesn't follow the rules of the Python language.
• They're also called parsing errors.
• The interpreter stops execution and displays an error message.
• These errors need to be rectified before the program can run.
• Fixing these errors usually means correcting grammar and following the Python syntax rules.

1.3 Exceptions

• Exceptions are errors that occur during program execution, even if the code is syntactically correct.
• Examples include attempting file operation on a non-existent file, or division by zero.
• These situations can be handled using specific exception handling blocks.
• An exception is a Python object that represents an error during execution.
• The program stops running unless the exception is handled.
• The exception object contains details about the error, like its type and location.

1.4 Built-in Exceptions

• Python's standard library has various pre-defined exceptions for common errors.
• These built-in exceptions represent specific types of error situations.
• They provide structured error handling, allowing programmers to write error handling routines to correct deviations and enhance program robustness.
• Examples include SyntaxError, ValueError, IOError, ZeroDivisionError.

1.5 Raising Exceptions

• Programmers can explicitly raise exceptions using the raise statement.
• Exceptions can be raised for specific conditions.
• Assert statements can also cause exceptions to be raised when conditions do not meet the programmer's expectations.

### 1.6 Handling Exceptions

• Exception handling allows you to gracefully manage and handle errors in your Python code.
• The try block encloses code that might raise an exception.
• The except block specifies how to handle particular exceptions caught in the try block.
• Else blocks are designed for code execution if no exceptions occur in the try block.
• A finally block is used for operations that should always happen, regardless of whether an exception occurs.

1.7 Finally Clause

• Statements written in the finally block are guaranteed to execute regardless of whether exceptions occur within the try block or not.
• Finally blocks are important for cleaning up resources like file closing.